McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes hepatocytes to a toxin that
selectively disrupts rough endoplasmic reticulum function
while leaving mitochondria intact. Several hours later, the
, cells demonstrate impaired plasma protein secretion
despite preserved ATP generation. Which cellular process
is most directly affected?
A. Oxidative phosphorylation
B. Translation of membrane-bound proteins
C. β-oxidation of fatty acids
D. Assembly of microtubules
Correct Answer: B
Rationale:
• Clinical Clue: Impaired secretion of plasma proteins with
preserved ATP production localizes dysfunction to protein
synthesis rather than energy metabolism.
• Mechanism: Rough endoplasmic reticulum (RER) contains
ribosomes responsible for synthesis of secreted and
membrane-associated proteins.
• Why the Correct Answer Is Right: Hepatocytes rely on RER
for synthesis of albumin, clotting factors, and other export
proteins.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation occurs in mitochondria.
o C. β-oxidation primarily occurs in mitochondria and
peroxisomes.
o D. Microtubule assembly depends mainly on
cytoskeletal proteins.
,• Exam Trap: Secretory failure does not necessarily imply
ATP depletion.
• High-Yield Clinical Correlation: Plasma cells possess
abundant RER because of intensive immunoglobulin
synthesis.
• Memory Anchor: “Rough ER = Ribosome-rich export
factory.”
Q2. A child develops recurrent respiratory infections and
infertility associated with immotile cilia syndrome.
Electron microscopy demonstrates absent dynein arms
within axonemal microtubules. This defect most directly
impairs which cellular function?
A. Vesicular trafficking
B. Cellular contraction
C. Motility generated by ATP-dependent microtubule
sliding
D. Synthesis of structural proteins
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent infections and infertility suggest
dysfunctional ciliary movement.
• Mechanism: Dynein arms hydrolyze ATP to generate
sliding between adjacent microtubules within cilia.
, • Why the Correct Answer Is Right: Coordinated microtubule
sliding drives effective ciliary beating.
• Why the Other Options Are Wrong:
o A. Vesicular trafficking primarily involves kinesin and
membrane vesicles.
o B. Muscle contraction depends on actin-myosin
interactions.
o D. Protein synthesis occurs at ribosomes.
• Exam Trap: Dynein dysfunction affects motility, not
microtubule formation itself.
• High-Yield Clinical Correlation: Primary ciliary dyskinesia
may present with situs inversus due to abnormal
embryonic ciliary motion.
• Memory Anchor: “Dynein drives directional ciliary
movement.”
Q3. A pathologist identifies extensive apoptosis in
lymphoid tissue after DNA damage from radiation
exposure. Which intracellular event most directly commits
the cell to programmed death?
A. Lysosomal rupture with enzymatic digestion
B. Activation of caspase cascades
C. Rapid depletion of intracellular ATP
D. Increased sodium influx across the membrane
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes hepatocytes to a toxin that
selectively disrupts rough endoplasmic reticulum function
while leaving mitochondria intact. Several hours later, the
, cells demonstrate impaired plasma protein secretion
despite preserved ATP generation. Which cellular process
is most directly affected?
A. Oxidative phosphorylation
B. Translation of membrane-bound proteins
C. β-oxidation of fatty acids
D. Assembly of microtubules
Correct Answer: B
Rationale:
• Clinical Clue: Impaired secretion of plasma proteins with
preserved ATP production localizes dysfunction to protein
synthesis rather than energy metabolism.
• Mechanism: Rough endoplasmic reticulum (RER) contains
ribosomes responsible for synthesis of secreted and
membrane-associated proteins.
• Why the Correct Answer Is Right: Hepatocytes rely on RER
for synthesis of albumin, clotting factors, and other export
proteins.
• Why the Other Options Are Wrong:
o A. Oxidative phosphorylation occurs in mitochondria.
o C. β-oxidation primarily occurs in mitochondria and
peroxisomes.
o D. Microtubule assembly depends mainly on
cytoskeletal proteins.
,• Exam Trap: Secretory failure does not necessarily imply
ATP depletion.
• High-Yield Clinical Correlation: Plasma cells possess
abundant RER because of intensive immunoglobulin
synthesis.
• Memory Anchor: “Rough ER = Ribosome-rich export
factory.”
Q2. A child develops recurrent respiratory infections and
infertility associated with immotile cilia syndrome.
Electron microscopy demonstrates absent dynein arms
within axonemal microtubules. This defect most directly
impairs which cellular function?
A. Vesicular trafficking
B. Cellular contraction
C. Motility generated by ATP-dependent microtubule
sliding
D. Synthesis of structural proteins
Correct Answer: C
Rationale:
• Clinical Clue: Recurrent infections and infertility suggest
dysfunctional ciliary movement.
• Mechanism: Dynein arms hydrolyze ATP to generate
sliding between adjacent microtubules within cilia.
, • Why the Correct Answer Is Right: Coordinated microtubule
sliding drives effective ciliary beating.
• Why the Other Options Are Wrong:
o A. Vesicular trafficking primarily involves kinesin and
membrane vesicles.
o B. Muscle contraction depends on actin-myosin
interactions.
o D. Protein synthesis occurs at ribosomes.
• Exam Trap: Dynein dysfunction affects motility, not
microtubule formation itself.
• High-Yield Clinical Correlation: Primary ciliary dyskinesia
may present with situs inversus due to abnormal
embryonic ciliary motion.
• Memory Anchor: “Dynein drives directional ciliary
movement.”
Q3. A pathologist identifies extensive apoptosis in
lymphoid tissue after DNA damage from radiation
exposure. Which intracellular event most directly commits
the cell to programmed death?
A. Lysosomal rupture with enzymatic digestion
B. Activation of caspase cascades
C. Rapid depletion of intracellular ATP
D. Increased sodium influx across the membrane
